[thirdparty/systemd.git] / src / resolve / resolved-etc-hosts.c

/* SPDX-License-Identifier: LGPL-2.1+ */

#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "fd-util.h"
#include "fileio.h"
#include "hostname-util.h"
#include "resolved-dns-synthesize.h"
#include "resolved-etc-hosts.h"
#include "string-util.h"
#include "strv.h"
#include "time-util.h"

/* Recheck /etc/hosts at most once every 2s */
#define ETC_HOSTS_RECHECK_USEC (2*USEC_PER_SEC)

static void etc_hosts_item_free(EtcHostsItem *item) {
        strv_free(item->names);
        free(item);
}

static void etc_hosts_item_by_name_free(EtcHostsItemByName *item) {
        free(item->name);
        free(item->addresses);
        free(item);
}

void etc_hosts_free(EtcHosts *hosts) {
        hosts->by_address = hashmap_free_with_destructor(hosts->by_address, etc_hosts_item_free);
        hosts->by_name = hashmap_free_with_destructor(hosts->by_name, etc_hosts_item_by_name_free);
        hosts->no_address = set_free_free(hosts->no_address);
}

void manager_etc_hosts_flush(Manager *m) {
        etc_hosts_free(&m->etc_hosts);
        m->etc_hosts_mtime = USEC_INFINITY;
}

static int parse_line(EtcHosts *hosts, unsigned nr, const char *line) {
        _cleanup_free_ char *address_str = NULL;
        struct in_addr_data address = {};
        bool found = false;
        EtcHostsItem *item;
        int r;

        assert(hosts);
        assert(line);

        r = extract_first_word(&line, &address_str, NULL, EXTRACT_RELAX);
        if (r < 0)
                return log_error_errno(r, "/etc/hosts:%u: failed to extract address: %m", nr);
        assert(r > 0); /* We already checked that the line is not empty, so it should contain *something* */

        r = in_addr_ifindex_from_string_auto(address_str, &address.family, &address.address, NULL);
        if (r < 0) {
                log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
                return 0;
        }

        r = in_addr_is_null(address.family, &address.address);
        if (r < 0) {
                log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
                return 0;
        }
        if (r > 0)
                /* This is an 0.0.0.0 or :: item, which we assume means that we shall map the specified hostname to
                 * nothing. */
                item = NULL;
        else {
                /* If this is a normal address, then simply add entry mapping it to the specified names */

                item = hashmap_get(hosts->by_address, &address);
                if (!item) {
                        r = hashmap_ensure_allocated(&hosts->by_address, &in_addr_data_hash_ops);
                        if (r < 0)
                                return log_oom();

                        item = new0(EtcHostsItem, 1);
                        if (!item)
                                return log_oom();

                        item->address = address;

                        r = hashmap_put(hosts->by_address, &item->address, item);
                        if (r < 0) {
                                free(item);
                                return log_oom();
                        }
                }
        }

        for (;;) {
                _cleanup_free_ char *name = NULL;
                EtcHostsItemByName *bn;

                r = extract_first_word(&line, &name, NULL, EXTRACT_RELAX);
                if (r < 0)
                        return log_error_errno(r, "/etc/hosts:%u: couldn't extract host name: %m", nr);
                if (r == 0)
                        break;

                found = true;

                r = dns_name_is_valid_ldh(name);
                if (r <= 0) {
                        log_warning_errno(r, "/etc/hosts:%u: hostname \"%s\" is not valid, ignoring.", nr, name);
                        continue;
                }

                if (is_localhost(name))
                        /* Suppress the "localhost" line that is often seen */
                        continue;

                if (!item) {
                        /* Optimize the case where we don't need to store any addresses, by storing
                         * only the name in a dedicated Set instead of the hashmap */

                        r = set_ensure_allocated(&hosts->no_address, &dns_name_hash_ops);
                        if (r < 0)
                                return log_oom();

                        r = set_put(hosts->no_address, name);
                        if (r < 0)
                                return r;

                        TAKE_PTR(name);
                        continue;
                }

                r = strv_extend(&item->names, name);
                if (r < 0)
                        return log_oom();

                bn = hashmap_get(hosts->by_name, name);
                if (!bn) {
                        r = hashmap_ensure_allocated(&hosts->by_name, &dns_name_hash_ops);
                        if (r < 0)
                                return log_oom();

                        bn = new0(EtcHostsItemByName, 1);
                        if (!bn)
                                return log_oom();

                        r = hashmap_put(hosts->by_name, name, bn);
                        if (r < 0) {
                                free(bn);
                                return log_oom();
                        }

                        bn->name = TAKE_PTR(name);
                }

                if (!GREEDY_REALLOC(bn->addresses, bn->n_allocated, bn->n_addresses + 1))
                        return log_oom();

                bn->addresses[bn->n_addresses++] = &item->address;
        }

        if (!found)
                log_warning("/etc/hosts:%u: line is missing any host names", nr);

        return 0;
}

int etc_hosts_parse(EtcHosts *hosts, FILE *f) {
        _cleanup_(etc_hosts_free) EtcHosts t = {};
        unsigned nr = 0;
        int r;

        for (;;) {
                _cleanup_free_ char *line = NULL;
                char *l;

                r = read_line(f, LONG_LINE_MAX, &line);
                if (r < 0)
                        return log_error_errno(r, "Failed to read /etc/hosts: %m");
                if (r == 0)
                        break;

                nr++;

                l = strchr(line, '#');
                if (l)
                        *l = '\0';

                l = strstrip(line);
                if (isempty(l))
                        continue;

                r = parse_line(&t, nr, l);
                if (r < 0)
                        return r;
        }

        etc_hosts_free(hosts);
        *hosts = t;
        t = (EtcHosts) {}; /* prevent cleanup */
        return 0;
}

static int manager_etc_hosts_read(Manager *m) {
        _cleanup_fclose_ FILE *f = NULL;
        struct stat st;
        usec_t ts;
        int r;

        assert_se(sd_event_now(m->event, clock_boottime_or_monotonic(), &ts) >= 0);

        /* See if we checked /etc/hosts recently already */
        if (m->etc_hosts_last != USEC_INFINITY && m->etc_hosts_last + ETC_HOSTS_RECHECK_USEC > ts)
                return 0;

        m->etc_hosts_last = ts;

        if (m->etc_hosts_mtime != USEC_INFINITY) {
                if (stat("/etc/hosts", &st) < 0) {
                        if (errno != ENOENT)
                                return log_error_errno(errno, "Failed to stat /etc/hosts: %m");

                        manager_etc_hosts_flush(m);
                        return 0;
                }

                /* Did the mtime change? If not, there's no point in re-reading the file. */
                if (timespec_load(&st.st_mtim) == m->etc_hosts_mtime)
                        return 0;
        }

        f = fopen("/etc/hosts", "re");
        if (!f) {
                if (errno != ENOENT)
                        return log_error_errno(errno, "Failed to open /etc/hosts: %m");

                manager_etc_hosts_flush(m);
                return 0;
        }

        /* Take the timestamp at the beginning of processing, so that any changes made later are read on the next
         * invocation */
        r = fstat(fileno(f), &st);
        if (r < 0)
                return log_error_errno(errno, "Failed to fstat() /etc/hosts: %m");

        r = etc_hosts_parse(&m->etc_hosts, f);
        if (r < 0)
                return r;

        m->etc_hosts_mtime = timespec_load(&st.st_mtim);
        m->etc_hosts_last = ts;

        return 1;
}

int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
        bool found_a = false, found_aaaa = false;
        struct in_addr_data k = {};
        EtcHostsItemByName *bn;
        DnsResourceKey *t;
        const char *name;
        unsigned i;
        int r;

        assert(m);
        assert(q);
        assert(answer);

        if (!m->read_etc_hosts)
                return 0;

        (void) manager_etc_hosts_read(m);

        name = dns_question_first_name(q);
        if (!name)
                return 0;

        r = dns_name_address(name, &k.family, &k.address);
        if (r > 0) {
                EtcHostsItem *item;
                DnsResourceKey *found_ptr = NULL;

                item = hashmap_get(m->etc_hosts.by_address, &k);
                if (!item)
                        return 0;

                /* We have an address in /etc/hosts that matches the queried name. Let's return successful. Actual data
                 * we'll only return if the request was for PTR. */

                DNS_QUESTION_FOREACH(t, q) {
                        if (!IN_SET(t->type, DNS_TYPE_PTR, DNS_TYPE_ANY))
                                continue;
                        if (!IN_SET(t->class, DNS_CLASS_IN, DNS_CLASS_ANY))
                                continue;

                        r = dns_name_equal(dns_resource_key_name(t), name);
                        if (r < 0)
                                return r;
                        if (r > 0) {
                                found_ptr = t;
                                break;
                        }
                }

                if (found_ptr) {
                        char **n;

                        r = dns_answer_reserve(answer, strv_length(item->names));
                        if (r < 0)
                                return r;

                        STRV_FOREACH(n, item->names) {
                                _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;

                                rr = dns_resource_record_new(found_ptr);
                                if (!rr)
                                        return -ENOMEM;

                                rr->ptr.name = strdup(*n);
                                if (!rr->ptr.name)
                                        return -ENOMEM;

                                r = dns_answer_add(*answer, rr, 0, DNS_ANSWER_AUTHENTICATED);
                                if (r < 0)
                                        return r;
                        }
                }

                return 1;
        }

        bn = hashmap_get(m->etc_hosts.by_name, name);
        if (bn) {
                r = dns_answer_reserve(answer, bn->n_addresses);
                if (r < 0)
                        return r;
        } else {
                /* Check if name was listed with no address. If yes, continue to return an answer. */
                if (!set_contains(m->etc_hosts.no_address, name))
                        return 0;
        }

        DNS_QUESTION_FOREACH(t, q) {
                if (!IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_AAAA, DNS_TYPE_ANY))
                        continue;
                if (!IN_SET(t->class, DNS_CLASS_IN, DNS_CLASS_ANY))
                        continue;

                r = dns_name_equal(dns_resource_key_name(t), name);
                if (r < 0)
                        return r;
                if (r == 0)
                        continue;

                if (IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_ANY))
                        found_a = true;
                if (IN_SET(t->type, DNS_TYPE_AAAA, DNS_TYPE_ANY))
                        found_aaaa = true;

                if (found_a && found_aaaa)
                        break;
        }

        for (i = 0; bn && i < bn->n_addresses; i++) {
                _cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;

                if ((!found_a && bn->addresses[i]->family == AF_INET) ||
                    (!found_aaaa && bn->addresses[i]->family == AF_INET6))
                        continue;

                r = dns_resource_record_new_address(&rr, bn->addresses[i]->family, &bn->addresses[i]->address, bn->name);
                if (r < 0)
                        return r;

                r = dns_answer_add(*answer, rr, 0, DNS_ANSWER_AUTHENTICATED);
                if (r < 0)
                        return r;
        }

        return found_a || found_aaaa;
}
Commit	Line	Data
53e1b683	1	/* SPDX-License-Identifier: LGPL-2.1+ */
dd0bc0f1	2
ca78ad1d ZJS	3	#include <sys/stat.h>
	4	#include <sys/types.h>
	5	#include <unistd.h>
	6
dd0bc0f1 LP	7	#include "fd-util.h"
	8	#include "fileio.h"
	9	#include "hostname-util.h"
dd0bc0f1	10	#include "resolved-dns-synthesize.h"
7c777a77	11	#include "resolved-etc-hosts.h"
dd0bc0f1 LP	12	#include "string-util.h"
	13	#include "strv.h"
	14	#include "time-util.h"
	15
	16	/* Recheck /etc/hosts at most once every 2s */
	17	#define ETC_HOSTS_RECHECK_USEC (2*USEC_PER_SEC)
	18
a1e92eee	19	static void etc_hosts_item_free(EtcHostsItem *item) {
37b7cc8d ZJS	20	strv_free(item->names);
	21	free(item);
	22	}
dd0bc0f1	23
a1e92eee	24	static void etc_hosts_item_by_name_free(EtcHostsItemByName *item) {
37b7cc8d ZJS	25	free(item->name);
	26	free(item->addresses);
	27	free(item);
	28	}
dd0bc0f1	29
78fc21a1	30	void etc_hosts_free(EtcHosts *hosts) {
37b7cc8d ZJS	31	hosts->by_address = hashmap_free_with_destructor(hosts->by_address, etc_hosts_item_free);
37b7cc8d ZJS	32	hosts->by_name = hashmap_free_with_destructor(hosts->by_name, etc_hosts_item_by_name_free);
fd373593	33	hosts->no_address = set_free_free(hosts->no_address);
37b7cc8d	34	}
dd0bc0f1	35
37b7cc8d ZJS	36	void manager_etc_hosts_flush(Manager *m) {
37b7cc8d ZJS	37	etc_hosts_free(&m->etc_hosts);
dd0bc0f1 LP	38	m->etc_hosts_mtime = USEC_INFINITY;
	39	}
	40
37b7cc8d	41	static int parse_line(EtcHosts hosts, unsigned nr, const char line) {
0351eb11 YW	42	_cleanup_free_ char *address_str = NULL;
0351eb11 YW	43	struct in_addr_data address = {};
fd373593	44	bool found = false;
dd0bc0f1	45	EtcHostsItem *item;
dd0bc0f1 LP	46	int r;
dd0bc0f1 LP	47
37b7cc8d	48	assert(hosts);
0351eb11	49	assert(line);
dd0bc0f1	50
0351eb11 YW	51	r = extract_first_word(&line, &address_str, NULL, EXTRACT_RELAX);
0351eb11 YW	52	if (r < 0)
bd005277 ZJS	53	return log_error_errno(r, "/etc/hosts:%u: failed to extract address: %m", nr);
bd005277 ZJS	54	assert(r > 0); /* We already checked that the line is not empty, so it should contain something */
0351eb11	55
7bf8c3de	56	r = in_addr_ifindex_from_string_auto(address_str, &address.family, &address.address, NULL);
bd005277 ZJS	57	if (r < 0) {
	58	log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
	59	return 0;
	60	}
0351eb11 YW	61
0351eb11 YW	62	r = in_addr_is_null(address.family, &address.address);
bd005277 ZJS	63	if (r < 0) {
	64	log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
	65	return 0;
	66	}
dd0bc0f1 LP	67	if (r > 0)
	68	/* This is an 0.0.0.0 or :: item, which we assume means that we shall map the specified hostname to
	69	* nothing. */
	70	item = NULL;
	71	else {
78fc21a1	72	/* If this is a normal address, then simply add entry mapping it to the specified names */
dd0bc0f1	73
37b7cc8d	74	item = hashmap_get(hosts->by_address, &address);
0351eb11	75	if (!item) {
37b7cc8d	76	r = hashmap_ensure_allocated(&hosts->by_address, &in_addr_data_hash_ops);
dd0bc0f1 LP	77	if (r < 0)
	78	return log_oom();
	79
0351eb11	80	item = new0(EtcHostsItem, 1);
dd0bc0f1 LP	81	if (!item)
	82	return log_oom();
	83
0351eb11	84	item->address = address;
dd0bc0f1	85
37b7cc8d	86	r = hashmap_put(hosts->by_address, &item->address, item);
dd0bc0f1 LP	87	if (r < 0) {
	88	free(item);
	89	return log_oom();
	90	}
	91	}
	92	}
	93
0351eb11 YW	94	for (;;) {
0351eb11 YW	95	_cleanup_free_ char *name = NULL;
dd0bc0f1 LP	96	EtcHostsItemByName *bn;
dd0bc0f1 LP	97
0351eb11 YW	98	r = extract_first_word(&line, &name, NULL, EXTRACT_RELAX);
0351eb11 YW	99	if (r < 0)
bd005277	100	return log_error_errno(r, "/etc/hosts:%u: couldn't extract host name: %m", nr);
0351eb11 YW	101	if (r == 0)
	102	break;
	103
fd373593 ZJS	104	found = true;
fd373593 ZJS	105
7470cc4c	106	r = dns_name_is_valid_ldh(name);
bd005277 ZJS	107	if (r <= 0) {
	108	log_warning_errno(r, "/etc/hosts:%u: hostname \"%s\" is not valid, ignoring.", nr, name);
	109	continue;
	110	}
	111
fd373593	112	if (is_localhost(name))
0351eb11	113	/* Suppress the "localhost" line that is often seen */
0351eb11	114	continue;
0351eb11	115
fd373593 ZJS	116	if (!item) {
	117	/* Optimize the case where we don't need to store any addresses, by storing
	118	* only the name in a dedicated Set instead of the hashmap */
	119
	120	r = set_ensure_allocated(&hosts->no_address, &dns_name_hash_ops);
0351eb11 YW	121	if (r < 0)
0351eb11 YW	122	return log_oom();
fd373593 ZJS	123
	124	r = set_put(hosts->no_address, name);
	125	if (r < 0)
	126	return r;
	127
	128	TAKE_PTR(name);
	129	continue;
0351eb11 YW	130	}
0351eb11 YW	131
fd373593 ZJS	132	r = strv_extend(&item->names, name);
	133	if (r < 0)
	134	return log_oom();
	135
37b7cc8d	136	bn = hashmap_get(hosts->by_name, name);
dd0bc0f1	137	if (!bn) {
37b7cc8d	138	r = hashmap_ensure_allocated(&hosts->by_name, &dns_name_hash_ops);
dd0bc0f1 LP	139	if (r < 0)
	140	return log_oom();
	141
	142	bn = new0(EtcHostsItemByName, 1);
	143	if (!bn)
	144	return log_oom();
	145
37b7cc8d	146	r = hashmap_put(hosts->by_name, name, bn);
dd0bc0f1	147	if (r < 0) {
dd0bc0f1 LP	148	free(bn);
	149	return log_oom();
	150	}
0351eb11 YW	151
0351eb11 YW	152	bn->name = TAKE_PTR(name);
dd0bc0f1 LP	153	}
dd0bc0f1 LP	154
fd373593 ZJS	155	if (!GREEDY_REALLOC(bn->addresses, bn->n_allocated, bn->n_addresses + 1))
fd373593 ZJS	156	return log_oom();
dd0bc0f1	157
fd373593	158	bn->addresses[bn->n_addresses++] = &item->address;
dd0bc0f1 LP	159	}
dd0bc0f1 LP	160
baaa35ad	161	if (!found)
bd005277	162	log_warning("/etc/hosts:%u: line is missing any host names", nr);
dd0bc0f1	163
0351eb11	164	return 0;
dd0bc0f1 LP	165	}
dd0bc0f1 LP	166
78fc21a1	167	int etc_hosts_parse(EtcHosts hosts, FILE f) {
37b7cc8d	168	_cleanup_(etc_hosts_free) EtcHosts t = {};
37b7cc8d ZJS	169	unsigned nr = 0;
	170	int r;
	171
7c777a77 LP	172	for (;;) {
7c777a77 LP	173	_cleanup_free_ char *line = NULL;
37b7cc8d ZJS	174	char *l;
37b7cc8d ZJS	175
7c777a77 LP	176	r = read_line(f, LONG_LINE_MAX, &line);
	177	if (r < 0)
	178	return log_error_errno(r, "Failed to read /etc/hosts: %m");
	179	if (r == 0)
	180	break;
	181
37b7cc8d ZJS	182	nr++;
37b7cc8d ZJS	183
bd005277 ZJS	184	l = strchr(line, '#');
	185	if (l)
	186	*l = '\0';
	187
37b7cc8d ZJS	188	l = strstrip(line);
	189	if (isempty(l))
	190	continue;
37b7cc8d ZJS	191
	192	r = parse_line(&t, nr, l);
	193	if (r < 0)
	194	return r;
	195	}
	196
be19cdf3	197	etc_hosts_free(hosts);
37b7cc8d ZJS	198	*hosts = t;
	199	t = (EtcHosts) {}; /* prevent cleanup */
	200	return 0;
	201	}
	202
452ca091	203	static int manager_etc_hosts_read(Manager *m) {
dd0bc0f1	204	_cleanup_fclose_ FILE *f = NULL;
dd0bc0f1 LP	205	struct stat st;
dd0bc0f1 LP	206	usec_t ts;
dd0bc0f1 LP	207	int r;
	208
	209	assert_se(sd_event_now(m->event, clock_boottime_or_monotonic(), &ts) >= 0);
	210
	211	/* See if we checked /etc/hosts recently already */
	212	if (m->etc_hosts_last != USEC_INFINITY && m->etc_hosts_last + ETC_HOSTS_RECHECK_USEC > ts)
	213	return 0;
	214
	215	m->etc_hosts_last = ts;
	216
	217	if (m->etc_hosts_mtime != USEC_INFINITY) {
	218	if (stat("/etc/hosts", &st) < 0) {
37b7cc8d ZJS	219	if (errno != ENOENT)
37b7cc8d ZJS	220	return log_error_errno(errno, "Failed to stat /etc/hosts: %m");
dd0bc0f1	221
37b7cc8d ZJS	222	manager_etc_hosts_flush(m);
37b7cc8d ZJS	223	return 0;
dd0bc0f1 LP	224	}
	225
	226	/* Did the mtime change? If not, there's no point in re-reading the file. */
	227	if (timespec_load(&st.st_mtim) == m->etc_hosts_mtime)
	228	return 0;
	229	}
	230
	231	f = fopen("/etc/hosts", "re");
	232	if (!f) {
37b7cc8d ZJS	233	if (errno != ENOENT)
37b7cc8d ZJS	234	return log_error_errno(errno, "Failed to open /etc/hosts: %m");
dd0bc0f1	235
37b7cc8d ZJS	236	manager_etc_hosts_flush(m);
37b7cc8d ZJS	237	return 0;
dd0bc0f1 LP	238	}
	239
	240	/* Take the timestamp at the beginning of processing, so that any changes made later are read on the next
	241	* invocation */
	242	r = fstat(fileno(f), &st);
	243	if (r < 0)
	244	return log_error_errno(errno, "Failed to fstat() /etc/hosts: %m");
	245
37b7cc8d	246	r = etc_hosts_parse(&m->etc_hosts, f);
be19cdf3	247	if (r < 0)
37b7cc8d	248	return r;
dd0bc0f1 LP	249
	250	m->etc_hosts_mtime = timespec_load(&st.st_mtim);
	251	m->etc_hosts_last = ts;
	252
	253	return 1;
dd0bc0f1 LP	254	}
	255
	256	int manager_etc_hosts_lookup(Manager m, DnsQuestion q, DnsAnswer **answer) {
	257	bool found_a = false, found_aaaa = false;
0351eb11	258	struct in_addr_data k = {};
dd0bc0f1	259	EtcHostsItemByName *bn;
dd0bc0f1 LP	260	DnsResourceKey *t;
	261	const char *name;
	262	unsigned i;
	263	int r;
	264
	265	assert(m);
	266	assert(q);
	267	assert(answer);
	268
86317087 YW	269	if (!m->read_etc_hosts)
	270	return 0;
	271
be19cdf3	272	(void) manager_etc_hosts_read(m);
dd0bc0f1 LP	273
	274	name = dns_question_first_name(q);
	275	if (!name)
	276	return 0;
	277
	278	r = dns_name_address(name, &k.family, &k.address);
	279	if (r > 0) {
	280	EtcHostsItem *item;
	281	DnsResourceKey *found_ptr = NULL;
	282
37b7cc8d	283	item = hashmap_get(m->etc_hosts.by_address, &k);
dd0bc0f1 LP	284	if (!item)
	285	return 0;
	286
	287	/* We have an address in /etc/hosts that matches the queried name. Let's return successful. Actual data
	288	* we'll only return if the request was for PTR. */
	289
	290	DNS_QUESTION_FOREACH(t, q) {
	291	if (!IN_SET(t->type, DNS_TYPE_PTR, DNS_TYPE_ANY))
	292	continue;
	293	if (!IN_SET(t->class, DNS_CLASS_IN, DNS_CLASS_ANY))
	294	continue;
	295
1c02e7ba	296	r = dns_name_equal(dns_resource_key_name(t), name);
dd0bc0f1 LP	297	if (r < 0)
	298	return r;
	299	if (r > 0) {
	300	found_ptr = t;
	301	break;
	302	}
	303	}
	304
	305	if (found_ptr) {
	306	char **n;
	307
	308	r = dns_answer_reserve(answer, strv_length(item->names));
	309	if (r < 0)
	310	return r;
	311
	312	STRV_FOREACH(n, item->names) {
	313	_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
	314
	315	rr = dns_resource_record_new(found_ptr);
	316	if (!rr)
	317	return -ENOMEM;
	318
	319	rr->ptr.name = strdup(*n);
	320	if (!rr->ptr.name)
	321	return -ENOMEM;
	322
	323	r = dns_answer_add(*answer, rr, 0, DNS_ANSWER_AUTHENTICATED);
	324	if (r < 0)
	325	return r;
	326	}
	327	}
	328
	329	return 1;
	330	}
	331
37b7cc8d	332	bn = hashmap_get(m->etc_hosts.by_name, name);
fd373593 ZJS	333	if (bn) {
	334	r = dns_answer_reserve(answer, bn->n_addresses);
	335	if (r < 0)
	336	return r;
	337	} else {
	338	/* Check if name was listed with no address. If yes, continue to return an answer. */
	339	if (!set_contains(m->etc_hosts.no_address, name))
	340	return 0;
	341	}
dd0bc0f1 LP	342
	343	DNS_QUESTION_FOREACH(t, q) {
	344	if (!IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_AAAA, DNS_TYPE_ANY))
	345	continue;
	346	if (!IN_SET(t->class, DNS_CLASS_IN, DNS_CLASS_ANY))
	347	continue;
	348
1c02e7ba	349	r = dns_name_equal(dns_resource_key_name(t), name);
dd0bc0f1 LP	350	if (r < 0)
	351	return r;
	352	if (r == 0)
	353	continue;
	354
	355	if (IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_ANY))
	356	found_a = true;
	357	if (IN_SET(t->type, DNS_TYPE_AAAA, DNS_TYPE_ANY))
	358	found_aaaa = true;
	359
	360	if (found_a && found_aaaa)
	361	break;
	362	}
	363
fd373593	364	for (i = 0; bn && i < bn->n_addresses; i++) {
dd0bc0f1 LP	365	_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
dd0bc0f1 LP	366
0351eb11 YW	367	if ((!found_a && bn->addresses[i]->family == AF_INET) \|\|
0351eb11 YW	368	(!found_aaaa && bn->addresses[i]->family == AF_INET6))
dd0bc0f1 LP	369	continue;
dd0bc0f1 LP	370
0351eb11	371	r = dns_resource_record_new_address(&rr, bn->addresses[i]->family, &bn->addresses[i]->address, bn->name);
dd0bc0f1 LP	372	if (r < 0)
	373	return r;
	374
	375	r = dns_answer_add(*answer, rr, 0, DNS_ANSWER_AUTHENTICATED);
	376	if (r < 0)
	377	return r;
	378	}
	379
4050e04b	380	return found_a \|\| found_aaaa;
dd0bc0f1	381	}